A memory device having a three-dimensional structure has been proposed in which a memory hole is formed in a stacked body in which a plurality of electrode layers are stacked, and a charge storage film and a semiconductor film are provided in the memory hole, extending in a stacking direction of the stacked body. The memory device has a plurality of memory cells connected in series between a drain-side select transistor and a source-side select transistor. The electrode layers in the stacked body are the drain-side select transistor, the source-side select transistor, and gate electrodes of the memory cells. A slit is formed in the stacked body, extending from an upper surface of the stacked body to a substrate. The slit is filled with a conductor. The conductor serves as a source line of a memory string, for example. When the conductor experiences, for example, a reduction in volume, the stacked body may experience peeling, the substrate may warp, and the like. It is desirable to relax stress in the conductor.